Chemical lace is a type of machine made lace. A chemical lace is prepared by embroidering a fabric comprised of water soluble fibers, with a water insoluble cotton or synthetic thread. The embroidered fabric is then placed in hot water in order to dissolve the soluble fabric, leaving the lace product. Chemical laces are used for table cloths, curtains, ladies' garments, etc.
Woven fabrics comprised of water soluble polyvinyl alcohol fibers have been used in the manufacture of water soluble fabrics, useful in the preparation of chemical laces. However, these woven fabrics are disadvantageously expensive since they are prepared by weaving yarns produced by spinning. Thin fabrics woven from polyvinyl alcohol fibers are even more expensive.
Although attempts have been made to employ non-woven rather than woven fabrics in order to lower the price of water soluble fabrics, non-woven fabrics having properties suitable for use in the preparation of chemical laces have not yet been obtained. Although non-woven fabrics having a high longitudinal tensile strength have been conventionally manufactured, it has been remarkably difficult to obtain non-woven fabrics having a weight per unit of area of 20 to 80 g/m.sup.2, a high tensile strength, and a low percent elongation in the direction of width, required of non-woven fabrics useful for preparing chemical laces.
The effective width of the conventional embroidering machine is 14.5 m. During the preparation of chemical lace, water soluble fabrics having a width larger than this width (14.5 m) are fed into the embroidering machine. The fabrics are always subjected to a tension of 1,000 to 1,500 kg. in the embroidering machine. When the elongation of the water soluble fabric in the direction of width is high relative to the tension, the embroidery pattern may slip out of position and, therefore, lace products of good quality are not obtained. In order to avoid this difficulty during the embroidering of water soluble fabrics, it is desirable for the elongation of the water soluble fabric to be as low as possible, while the tensile strength of the water soluble fabric is as high as possible.
With respect to conventional non-woven fabrics in which webs composed of hot water soluble polyvinyl alcohol fibers are merely combined with each other, the combination of fibers is destroyed by driving an embroidery needle into the non-woven fabrics, and this generates "slackness" in the fabric since an embroidery needle is driven into the fabric with a high tension, while non-woven fabrics naturally have a quite low tensile strength.
It is an object of the present invention to provide a method of manufacturing water soluble fabrics for chemical laces without the above described defects, that is to say, a water soluble fabric having a low percent elongation in the direction of the width of the fabric as well as a high tensile strength.